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排序方式: 共有419条查询结果,搜索用时 15 毫秒
121.
Sylwia Belica-Pacha Mateusz Dako Vyacheslav Buko Ilya Zavodnik Katarzyna Miowska Maria Bryszewska 《International journal of molecular sciences》2021,22(22)
The interaction between sertraline hydrochloride (SRT) and randomly methylated β-cyclodextrin (RMβCD) molecules have been investigated at 298.15 K under atmospheric pressure. The method used—Isothermal Titration Calorimetry (ITC) enabled to determine values of the thermodynamic functions like the enthalpy (ΔH), the entropy (ΔS) and the Gibbs free energy (ΔG) of binding for the examined system. Moreover, the stoichiometry coefficient of binding (n) and binding/association constant (K) value have been calculated from the experimental results. The obtained outcome was compared with the data from the literature for other non-ionic βCD derivatives interacting with SRT and the enthalpy-entropy compensation were observed and interpreted. Furthermore, the connection of RMβCD with SRT was characterized by circular dichroism spectroscopy (CD) and complexes of βCD derivatives with SRT were characterized through the computational studies with the use of molecular docking (MD). 相似文献
122.
Yulia V. Vakhitova Tatiana S. Kalinina Liana F. Zainullina Anastasiya Yu. Lusta Anna V. Volkova Nikita V. Kudryashov Tatiana A. Gudasheva Alexander A. Shimshirt Ilya A. Kadnikov Mikhail V. Voronin Sergei B. Seredenin 《International journal of molecular sciences》2021,22(24)
Induction of BDNF-TrkB signaling is associated with the action mechanisms of conventional and fast-acting antidepressants. GSB-106, developed as a small dimeric dipeptide mimetic of BDNF, was previously shown to produce antidepressant-like effects in the mouse Porsolt test, tail suspension test, Nomura water wheel test, in the chronic social defeat stress model and in the inflammation-induced model of depression. In the present study, we evaluated the effect of chronic per os administration of GSB-106 to Balb/c mice under unpredictable chronic mild stress (UCMS). It was observed for the first time that long term GSB-106 treatment (1 mg/kg, 26 days) during ongoing UCMS procedure ameliorated the depressive-like behaviors in mice as indicated by the Porsolt test. In addition, chronic per os administration of GSB-106 resulted in an increase in BDNF levels, which were found to be decreased in the prefrontal cortex and hippocampus of mice after UCMS. Furthermore, prolonged GSB-106 treatment was accompanied by an increase in the content of pTrkB706/707 in the prefrontal cortex and by a pronounced increase in the level of pTrkB816 in both studied brain structures of mice subjected to UCMS procedure. In summary, the present data show that chronic GSB-106 treatment produces an antidepressant-like effect in the unpredictable chronic mild stress model, which is likely to be associated with the regulation of the BDNF-TrkB signaling. 相似文献
123.
Ilya Lyagin Nikolay Stepanov George Frolov Elena Efremenko 《International journal of molecular sciences》2022,23(3)
To obtain fiber materials with pronounced chemical-biological protection, metal (Zn or Ta) nanoparticles were jointly applied with polyelectrolyte complexes of enzymes and polypeptides being their stabilizers. Computer modeling revealed the preferences between certain polyelectrolyte partners for N-acyl-homoserine lactone acylase and hexahistidine-tagged organophosphorus hydrolase (His6-OPH) possessing the quorum quenching (QQ) behavior with bacterial cells. The combinations of metal nanoparticles and enzymes appeared to function better as compared to the combinations of the same QQ-enzymes with antibiotics (polymyxins), making it possible to decrease the applied quantities by orders of magnitude while giving the same effect. The elimination of Gram-positive and Gram-negative bacterial cells from doubly modified fiber materials notably increased (up to 2.9-fold), whereas His6-OPH retained its hydrolytic activity in reaction with organophosphorus compounds (up to 74% of initially applied activity). Materials with the certain enzyme and Zn nanoparticles were more efficient against Bacillus subtilis cells (up to 2.1-fold), and Ta nanoparticles acted preferentially against Escherichia coli (up to 1.5-fold). Some materials were proved to be more suitable for combined modification by metal nanoparticles and His6-OPH complexes as antimicrobial protectants. 相似文献
124.
Ilya Kolyadenko Anastasia Scherbakova Kirill Kovalev Azat Gabdulkhakov Svetlana Tishchenko 《International journal of molecular sciences》2022,23(1)
Laccases catalyze the oxidation of substrates with the concomitant reduction of oxygen to water. Recently, we found that polar residues located in tunnels leading to Cu2 and Cu3 ions control oxygen entrance (His 165) and proton transport (Arg 240) of two-domain laccase (2D) from Streptomyces griseoflavus (SgfSL). In this work, we have focused on optimizing the substrate-binding pocket (SBP) of SgfSL while simultaneously adjusting the oxygen reduction process. SgfSL variants with three single (Met199Ala, Met199Gly, and Tyr230Ala) and three double amino acid residues substitutions (Met199Gly/His165Ala, His165Ala/Arg240His, Met199Gly/Arg240His) were constructed, purified, and investigated. Combination of substitutions in the SBP and in the tunnel leading to Cu2 ion (Met199Gly/Arg240His) increased SgfSL catalytic activity towards ABTS by 5-fold, and towards 2.6-DMP by 16-fold. The high activity of the Met199Gly/Arg240His variant can be explained by the combined effect of the SBP geometry optimization (Met199Gly) and increased proton flux via the tunnel leading to Cu2 ion (Arg240His). Moreover, the variant with Met199Gly and His165Ala mutations did not significantly increase SgfSL’s activity, but led to a drastic shift in the optimal pH of 2.6-DMP oxidation. These results indicate that His 165 not only regulates oxygen access, but it also participates in proton transport in 2D laccases. 相似文献
125.
The efficiency of radio-frequency (RF) power absorption, RF magnetic field structure and
plasma parameters were measured in cylindrical inductive RF plasma sources 20 cm in diameter
and 22, 32, 53 cm in length with a low value external magnetic field. The experiments were
carried out in argon at pressures of 13–140 mPa. The RF power supply changed from 200 W to
800 W. The spiral antenna was used for sustaining the discharge. It was shown that efficiency of
RF power absorption depended nonlinearly on the external magnetic field values. At maximal
values of the RF power absorption efficiency, the axial distributions of longitudinal Bz and
azimuthalBcomponents of RF magnetic field manifested the formation of the partially standing
wave with a half wavelength close to 8 cm. At the same conditions, the axial dependence of the
radial RF magnetic field component Br differed drastically. It was concluded that the Bz and Bamplitudes were largely determined by the RF field of Trivelpiece-Gould wave, while Br amplitude represented the radial RF field of the helicon wave. 相似文献
126.
Mikhail V. Voronin Ilya A. Kadnikov Liana F. Zainullina Ilya O. Logvinov Ekaterina R. Verbovaya Tatyana A. Antipova Yulia V. Vakhitova Sergei B. Seredenin 《International journal of molecular sciences》2021,22(23)
The ability of NQO2 to increase the production of free radicals under enhanced generation of quinone derivatives of catecholamines is considered to be a component of neurodegenerative disease pathogenesis. The present study aimed to investigate the neuroprotective mechanisms of original NQO2 inhibitor M-11 (2-[2-(3-oxomorpholin-4-il)-ethylthio]-5-ethoxybenzimidazole hydrochloride) in a cellular damage model using NQO2 endogenous substrate adrenochrome (125 µM) and co-substrate BNAH (100 µM). The effects of M-11 (10–100 µM) on the reactive oxygen species (ROS) generation, apoptosis and lesion of nuclear DNA were evaluated using flow cytometry and single-cell gel electrophoresis assay (comet assay). Results were compared with S29434, the reference inhibitor of NQO2. It was found that treatment of HT-22 cells with M-11 results in a decline of ROS production triggered by incubation of cells with NQO2 substrate and co-substrate. Pre-incubation of HT-22 cells with compounds M-11 or S29434 results in a decrease of DNA damage and late apoptotic cell percentage reduction. The obtained results provide a rationale for further development of the M-11 compound as a potential neuroprotective agent. 相似文献
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Important components of molecular modeling applications are estimation and minimization of the internal energy of a molecule.
For macromolecules such as proteins and amino acids, energy estimation is performed using empirical equations known as force
fields. Over the past several decades, much effort has been directed towards improving the accuracy of these equations, and
the resulting increased accuracy has come at the expense of greater computational complexity. For example, the interactions
between a protein and surrounding water molecules have been modeled with improved accuracy using the generalized Born solvation
model, which increases the computational complexity to O (n
3). Fortunately, many force-field calculations are amenable to parallel execution. This paper describes the steps that were
required to transform the Born calculation from a serial program into a parallel program suitable for parallel execution in
both the OpenMP and MPI environments. Measurements of the parallel performance on a symmetric multiprocessor reveal that the
Born calculation scales well for up to 144 processors. In some cases the OpenMP implementation scales better than the MPI
implementation, but in other cases the MPI implementation scales better than the OpenMP implementation. However, in all cases
the OpenMP implementation performs better than the MPI implementation, and requires less programming effort as well.
Trademark Legend Sun, Sun Microsystems, SPARC, UltraSPARC, Sun Fire, Sun Performance Library and Sun HPC Cluster Tools are
trademarks or registered trademarks of Sun Microsystems, Inc. in the United States and other countries. 相似文献